A demonstrator attends a protest against fare hikes for city buses in Rio de Janeiro January 16, 2015. Amid a marked economic downturn and high inflation, bus fares went up in Sao Paulo, Brazil's largest city, from 3 to 3.50 reais, and in Rio, the former capital, from 3.0 to 3.40 reais. (Photo by Mauro Pimentel/Reuters)

A demonstrator holds a sign thats reads, “Fighting is not a crime!” during a protest against fare hikes for city buses in Rio de Janeiro January 16, 2015. (Photo by Mauro Pimentel/Reuters)

Riot police block a street as demonstrators use makeshift shields painted with the colours of the Palestinian flag during a protest against fare hikes for city buses in Rio de Janeiro January 16, 2015. (Photo by Mauro Pimentel/Reuters)

Demonstrators use makeshift shields painted with the colours of the Palestinian flag during a protest against fare hikes for city buses in Rio de Janeiro January 16, 2015. (Photo by Mauro Pimentel/Reuters)

A demonstrator shows a 2.00 reais bill, the old transport fee of city buses, during a protest against fare hikes for city buses in Rio de Janeiro January 16, 2015. (Photo by Mauro Pimentel/Reuters)

Demonstrators march in front of a line of riot police during a protest against fare hikes for city buses, subway and trains in Sao Paulo January 16, 2015. Brazilian police fired tear gas to disperse hundreds of people protesting an increase in transit fares in Sao Paulo, the country's biggest city, on Friday, raising fears of more disruption after a similar demonstration turned violent last week. The banner (in red) reads “No to fare hikes”. (Photo by Nacho Doce/Reuters)

Riot police stand in front of a sign that reads, “No to fare hikes” hung on the gate of a house during a protest against fare hikes for city buses, subways and trains in Sao Paulo January 16, 2015. (Photo by Nacho Doce/Reuters)

A demonstrator (L) holds up a sign that reads, “No to fare hikes”, next to riot police in front of the town hall during a protest against fare hikes for city buses, subway and trains in Sao Paulo January 16, 2015. (Photo by Nacho Doce/Reuters)

Passengers riding inside a city bus hold up signs to the window that read, “No to fare hikes”, during a protest against fare hikes for city buses, subways and trains in Sao Paulo January 16, 2015. (Photo by Nacho Doce/Reuters)

People sitting on top of a wall hold signs that read, “No to fare hikes”, as riot police walk past below, during a protest against fare hikes for city buses, subways and trains in Sao Paulo January 16, 2015. (Photo by Nacho Doce/Reuters)

Riot police fire tear gas at demonstrators during a protest against fare hikes for city buses, subways and trains in Sao Paulo January 16, 2015. (Photo by Nacho Doce/Reuters)

Riot police detain a demonstrator during a protest against fare hikes for city buses, subway and trains in Sao Paulo January 16, 2015. (Photo by Nacho Doce/Reuters)